1. Field of the Invention
The present invention relates to copolymers of hydroxyalkyl vinyl ethers, adducts of C.sub.2 -C.sub.4 -alkylene oxides with hydroxyalkyl vinyl ethers and/or polytetrahydrofuran vinyl ethers and, if desired, other copolymerizable monomers and the use of the stated copolymers and of hydroxyalkyl vinyl ethers which have been polymerized by cationic or free radical polymerization and contain the monomers (a) or (b) as sole monomers or as a mixture with other copolymerizable monomers, as viscosity depressants for surfactants and as additives for detergents and cleaning agents.
2. Description of the Related Art Including Information Disclosed Under 37 C.F.R. .sctn.1.97-1.99
U.S. Pat. No. 2,104,004 discloses a process for the cationic polymerization of vinyl ethers, in which from 0.001 to 5% by weight of a virtually anhydrous inorganic acid are used as the catalyst. Examples of suitable catalysts are aluminum chloride, iron chloride, sulfuric acid, hydrochloric acid and boron trifluoride.
US-B-26 407 discloses the free radical copolymerization of divinyl compounds, such as divinyl ether, divinyldimethylsilane or divinyl sulfone, with monoethylenically unsaturated monomers, e.g. vinyl acetate, maleic anhydride or dimethyl fumarate. Suitable catalysts are peroxy compounds, such as di-tert-butyl peroxide, hydrogen peroxide, alkyl hydroperoxides and diacyl peroxides. Ziegler catalysts are also suitable for initiating the polymerization. The polymers obtainable in this manner are fiber-forming and film-forming and can be used for the production of coatings or packaging materials. They are also suitable as lubricants, lubricant additives and adhesives, and as crosslinking agents for epoxy resins.
U.S. Pat. No. 3,328,468 discloses the preparation of homopolymers of the monovinyl ether of diethylene glycol using polymerization initiators which form free radicals under the polymerization conditions. The hydroxyl group of the monovinyl ethers of diethylene glycol remains virtually unchanged during the free radical polymerization. The polymers obtainable in this manner can replace polyols in foam production. As also disclosed in this publication, monovinyl ethers of diols can be polymerized under the action of cationic initiators with the formation of polyacetals.
EP-A-0 359 055 discloses detergent formulations which contain from 0.5 to 65% by weight of a surfactant and from 1 to 80% by weight of a builder which consists of a polymer which is obtainable by free radical copolymerization of divinyl ether and maleic anhydride in a molar ratio of 1:2 and subsequent hydrolysis of the anhydride groups and neutralization.
EP-A-0 379 166 discloses, inter alia, copolymers of alkyl vinyl ethers and hydroxyl-containing vinyl ethers, such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether or hydroxybutyl vinyl ether, and alkoxylates of these hydroxyl-containing vinyl ethers. The copolymers are used in coating and molding materials for improving the leveling and as an antifoam.
U.S. Pat. No. 3,131,162 discloses the copolymerization of monovinyl ethers of glycols with vinyl esters of saturated fatty acids having a carbon chain of not more than 6 carbon atoms in the presence of peroxides. The copolymers can be vulcanized to give rubber-like materials with the addition of conventional vulcanization assistants.